Default behavior in SmartConfig was wrong. What it should be (and now is) is
when a value is requested but not present, the value is set and returned with
the default if given, or null is returned if no default is given.
* Changed the behavior of SmartConfig when setting file type properties. Now it
tries to coerce the given value into a File object if it is not already a File
object.
* Changed the behavior of SmartConfig when retrieving a property without
specifying a default value. Now it returns null if the property is not set and
no default is given.
Jonathan Bernard